Centrifugal pump.



PATENTED OCT. 9, 1906.

w. 1. BBTTIS. GENT-RIPUGAL PUMP.

@9i lucasca PATENTED OCT. 9, 1906.

z SHEETS-SHEET 2.

W. I. BETTIS. GENTRIFUGAL PUMP. APPLIGATION FILED FEB 1s 1905 WILLIAM IRVIN BETTIS, OF HOUSTON, TEXAS, ASSIGNOR OF ONE-HALF TO HUGH HAMILTON. OF HOUSTON. TEXAS.

CENTRIFUGAL PUMP..

v No. 832.651.

Specicationof Letters Patent.' Application filed February 13, 1905. Serial No. 245,517.

Patented Oct. 9, 1906.

To a/ZZ whom it may concern.'

Beit known that I, WILLIAM IRvIN BET- TIs, a citizen of the United States, residing at Houston, in the county of Harris and State of Texas, have invented certain new and useful Improvements in Centrifugal Pumps, 'of which the following is a specification.

My invention relates to centrifu al pumps of the class in which a rotary impel er having a fluid-entrance at the eye 'empties into a surrolnding discharge-chamber.

n 241,666, iile January 18, 1905, I have shown a centrifugal pump of this general class in which an incased impeller composed of side disks and intervening substantially radial vanes receives iiuid at the eye and discharges it into a surrounding volute or annular chamber which communicates with chambersv side chambers of the fluid used in priming,

but the periphery of the impeller is so formed asto cause any fluid that might tend to flow' into the side chambers from the dischargechamber 4while the pump is in operation to be thrown back to the dlscharge-chamber Aby centrifugal force. A v

According to my present invention I provide the impeller with vanes arranged outside the periphery of the impeller-vanes and v working in annular chambers 'interposed between the discharge chamber and the side chambers of the pump and which operate not only to empty said side chambers, but

also toproduce a centrifugal force greater than that produced by the main or usual vanes of the impellerand prevent luidfrom. rentering said side chambers.

Other features of invention used in connection with those above outlined will be hereshows a horizontal central section of a cenmy application for patent, Serial No.

trifugal pump embodying my presentl improvements. Fig.. 2 is a detail view in perspective, illustrating the relation between the vanes of the` impeller and the stationary or inlet vanes through which the fluid passes .from the supply-passage to .the impeller.

Fig. 3 is a detail view of a portion of the rim or periphery of the impeller constructed in the .form shown in Fig. 1. Fig. 4 is a detail view, in section and on an enlarged scale, of the devices constructed in accordance with my present inventionto empty the side chambers of the pump and prevent p fluid from rentering them. Fig. 5 shows a vertical section on the line 5 5 of Fig. 1. showsa vertical transverse section of a portion of a pump embodying my improvements with some ofthe parts constructed differently from those shown in Fig. 1. Fig. 7 shows a vertical section on the line 7 7 vof Fig. 6.

Many parts of the pump shown in the drawings are similar' to those shown in my prior application; but foi clearness the general construction and arrangement of the pumps shown will be described, as well as the special parts embodying my present improvements. f'

The impeller A (shown in' Fig. 1) is composed of two side plates or disks a; arranged a suitable distance apart and connected by intervening vanes B, which divide the space between the disks intera series of chambers- B through which the-Huid passes. The vanes are connected with a centrally-arranged hub C, fast on the driving-shaft D. The outer edges of the'disks are arranged a suitable distance apart to form a contracted annular discharge orifice or throat E, which runs-close to the throat f ofv corresponding width in the volutejor annular dischar echamber F. In the pump having a dou le supply, as illustrated in Fi 1, the vanes B are branched or bifurcate and extend in- Fig. 6

wardly on opposite sides of the hub C. The i outer portions ofthe chambers B are of approximately the same Width from the edge of the hub C to the throat E, the inner sides of the disks being nearly parallel until they approach close to the throat, where the sides are curved or tapered toward the throat.. i In this way the chambers are made Wide just inside the-throat, and a pressure is produced at the throat,', while the radial' velocity of the fluid is greatly reduced.

IOO

As the velocity of the fluid within the impeller is reduced at the outer portion of the impeller-chambers the friction of the fluid on the walls of the impeller-chambers is materially reduced, and thus the efficiency of the pump is enhanced.

The fluid enters the impeller through the supply-passages at opposite sides thereof. These passages on each side are formed in a casing G,.provided with an entrance-port g, which communicates with a chamber g', surrounding the vdriving-shaft D and having a hub g2 extending within the plane of the impeller and beyond the inner edgesof the impeller-vanes to the hub C. The fluid which enters at g passes into the annular chamber g and is directed into the impeller in such manner as to partake of the direction of movement of the impeller and to be delivered at the general angle in` which the im ellenvanes are arranged. In this way the oss of energy due to shock of entrance is avoided or at any rate very materially reduced.

In the drawings I have shown a series of inlet-vanes H in the supply-passages at the inner ends of the impeller-vanes, which is so constructed as to reduce the area ofthe entrance-port, and consequently increase the initial velocity of the fluid. The construe# tion is also such as to change the direction of flow of the fluid to the impeller in the manner before stated, and thus reduce or obviate entirely the loss of energy due to the shock of entrance. The Aform of the inlet-vanes is clearly indicated in Fig. 2, where, as will be seen, the casing G is provided with an annular series of o. enings h, through which the fluid passes, t ese openings being separated byy vanes h', which are properly inclined to direct the fluid in the proper direction in the manner before described. The construction of the casings of the entrance-passages and of the vanes on opposite sides of the pump are precisely the same.

The impeller is inclosed in a fixed casing consisting of two annular frame-pieces or sections I on opposite sides of the impeller. At their periphery the casing-sections are bolted to the flanges c of the volute or annular discharge-chamber F but between these flanges and the lates are interposed rings S for a purposey ereinafter described. In Fi l I have shown the periphery of the impe ler as tapered in the manner described in my prior application, and I have also shown the ta-V pered periphery as' formed with radial grooves 0.2.

The edges ofthe casing-sections are inclined Vvor tapered correspondingly with the talpered periphery of the impeller, being paral el therewith, but arranged a short distance therefrom, leaving a clear but narrow space for the assage of fluid from the chambers J p)f the ed casing to the discharge-chamer F.

The chambers J of the casing are annular and in Fig. 1 are on opposite sides of the impeller. They communicate with the throat E and also, the throatf at the periphery of -the impeller through the narrow annular passages above referred to. The casing -sections carry radially-arranged ribs K, which are Afor the purpose of preventing a rotary movement of the Huid within the chamber J when the pump is first started.

In Fig. 1 I have shown an impeller formed with a tapered periphery, and this, as de scribed in my prior application, operates to, throw back by centrifugal force any fluid that may tend to pass from the dischargechamber to the side chambers of thepump;

but in lieu of this construction (see Fig. 6) or as supplementary to it, as shown in Fig. 1, I provide the following devices: To opposite sides of the impeller near its periphery are secured flat rings or annular plates P, each of which projects outward beyond the periphery of the impeller and carries a series of substantially radial vanes p, which are preferably curved in the manner shown in Fig.V4 7. These vanes rotate in paths outside the path described by the outer edges of the vanes B ofthe impeller, and thus generate a greater centrifugal force than the'vanes B.

The rings P and theirvanes p operate in annular chambers Q, formed in the fixed casing-sections I around the chambers J, and they communicate with the discharge-chamber F through the passages a: and The vanes p ofeach plate are arranged close to one wall`of the chamber Q, and the opposite wall of each chamber Qis provided with stationary radial ribs R. Preferably the ribs R are formed on rings S, which are interposed between the flanges e of the discharge-chamber and the casing-sections I, as by this construction the parts may be more easily assembled.

To avoid any possibility of leakage at the eye, the casing G on each side of the pump is formed with an annular chamber L, within whichis arranged an annular plate or ring M,

IOS

TIO

bolted to the impeller and rotating therewith.

The 4annular plate extends into the-chamber L beyond the inner edges of the casing-section, and it is formed with radial ribs l, ar-

ranged close to, without touching, the outer side of the 'casing-section next the chamber L. The casin G within the annular chamber L is forme with stationary radial ribs l', lying close to the outer face of the plate M.

These ribs terminate a short distance from This is chamber with a loa lowing Way: As the impeller rotates, any

Ailuid which may pass out of the joint y and into the chamber L Will be thrown outward by centrifugal force and carried around at the outer end of the chamber L, and this centrifugal force issuch that no fluid will pass down into the joint z. In this way a rotary fluid seal is formed which Will absolutely prevent any fluid entering at the eye of the pump from passing into the chambers of the casing.

It might happen that if a complete vacuum is'formedin the chambers J the fluid would tend to enter them, and it may be desirable to admit air to the chambers to displace fluid after the fluid has been Withdrawn therefrom and after the pressure in the chambers has been reduced to a predetermined amount. For this dpurpose I provide each ed valve T, of any suitable construction, which is so constructed that normally it Will beheld closed, but after the pressure within the chambers has been reduced to a suilicient amount the valves will automatically open to admit air, and thus prevent the entrance of fluid.

p In F ig. 6 the construction-.of the pump is shown as substantially `the same as that shown in Fig. 1, the most important difference being that the periphery of the impeller is not tapered, as the centrifugal force generated by the vanes p is sufficient to prevent the backilow of fluid from the dischargechamber to the chambers of the pump-casing. In this case also the plates S are omitted, and the ribs R are formed on or secured to the flanges e of the discharge-chamber.

In the operation of my improved pump the impeller, casing-chambers, and supply-passages are all rlirst completely lled with the iluid to be pumped in order to prime the pump. Then a rotary movement is imparted to the impeller, and the fluid is discharged through the throat lof the impeller. The chambers J being at this time filled with the fluid, a side pressure is exerted on the impeller and also a detrimental side .friction vwhich it is desirable to avoid. In my improved pump soon after the rotary movement of the impeller commences the fluid in the chambers J passes out through the passages a: by gravity and also and principallyby the centrifu al force generated by the vanes p. This centri gal force is also aided by the injector force caused by the rush of fluid through the throats E and f, and in the construction shown in Fig.

1 the action is further aided by the tapered and grooved periphery of the impeller. In th1s way the chambers J are 'uickly em tied, and the air-pressure Within t em is re uced, thus relieving the impeller entirely from friction on its sides.

Normally the valves T are closed, and they y are so weighted as to remain closed while the chambers J are being emptied; but when the .vacuum in the chambers J exceeds the tension of the springs t the valves automatically open and admit air to the chambers J.

If by reason of increased pressure in the discharge-chamber or any other cause the fluid tends to pass inwardly through the passages a: to the chambers J, it will be prevented from entering said chambers by the rotary vanes p, which by their centrifugal action will hold any fluid which tends to enter the chambers J within the annular chambers Q and Will force back into the discharge-chamber such fluid should it tend to enter the chambers J in large a'mounts.

In order to prevent the fluid from rotating in the chambers Q between the inner sides of the plates P and the casing, the ribs R, before referred to, are employed. These act as baffle-plates, but permit the fluid to pass easily into the passages w.

It will be understood that many features of the pump herein shown and described are similar to those described and claimed in my before-mentioned application.

The claims in the present application relate to the vanes p and parts coperating therewith and also to the valves T, which permit the air to enter the chambers J at the sion of this kind.

I claim as my invention l 1. A centrifugal pump comprising a rotary impeller, a discharge-chamber with Which it communicates, a fixed chambered casing for the impeller also communicating with the discharge-chamber and a series of vanescarried by the impeller which traverses a path IOO outside that traversed by the main impellervanes.

2. A centrifugal pump comprising a rotary impeller, divided into chambers by varies, a

discharge-chamber communicating with the chambers of the impeller, a fixed casing for the impeller having side chambers also co'mmunicating with the discharge-chamber and vanes carried by the impeller interposed between the side chambers and the dischargechamber and which rotate ata greater speed than that of the impeller-vanes for. the purpose specified.

3. A centrifugal pump comprising a rotary impeller composed of side disks or plates. and linterposed vanes dividing the impeller into a series of chambers, a dischar e-chamber communicating with the cham ers of the impeller, a fixed casing having a chamber at the side of theimpeller also communicating with the discharge-chamber and having also an annular chamber outside the path traversed by the impeller-vanas and a series of vanes carried by the impeller in said annular ISO chamber and which travel at a greater speed than the impeller-vanes.

4. In a centrifugal pump of the class in which a xed chambered casing incloses a rotary charnbered impeller discharging into a surrounding chamber, the combination with the impeller, of vanes carried thereby vfixed chambered casing inc osing the iin-- peller and having a tapered or inclined com- Inunication between its chamber and the discharge-chamber and a series of vanes carried by the impeller which travel at a greater speed than the impeller-vanes and are interposed between the chamber in the Xed casing andthe discharge-chamber.

6. A centrifugal pump'c'omprising an imeller having a c ontracted discharge-throat ormed in its periphery, a discharge-chamber surrounding the impeller and communicating therewith, a xed chambered casing inclosing the impeller and communicating with the discharge-chamber and a series of vanes vided with vanes on its periphery travelingv at a greater speed than the impeller-vanes and operating to prevent the backiiow of fluid Jfrom the discharge-chamber to the inside of the casing.

8. In a centri l(gal pump, lthe combination of a rotary impe ler, 'a discharge-chamber with which it4 communicates, a chambered casing inclosing the'impeller and communicating with the discharge-chamber, devices carried by the impeller which travel at a greater speed than the impeller-vanes and prevent the backflow of i'luid to the charnbered casing and a valve for admitting air to the inside of the ohambered casing when-the pressure thereinhas been reduced to a predetermined extent.

In testimony whereofI have hereunto subscribed Iny name.

.WILLIAM IRv'iN'Burris` Witnesses ALLEN PAUL, J. LoEwENsTEIN. 

